Device for effecting the narrowing in knitting machines and suchlike



Dec. 22, 1964 G. AZZOLARI 3,162,027.

DEVICE FOR EFFECTING THE NARROWING IN KNITTING I MACHINES AND SUCHLIKE Filed Dec. 28, 1960 4 Sheets-Sheet l INVENTOR Dec. 22, 1964 A oLARl 3,162,027

DEVICE FOR EFFE NG E NARROWING IN KNITTING MACHINES AND SUCHLIKE Filed Dec. 28, 1960 4 Sheets-Sheet 2 A QZ I IIIIIIL I I m ul ml 4 INVENTOR Gl/fda fl oia/"f Dec. 22, 1964 G. AZZOLARI 3,162,027

DEVICE FOR EFFECTING THE NARROWING IN KNITTING MACHINES AND SUCHLIKE Filed Dec. 28, 1960 4 Sheets-Sheet 5 Z I INVENFOR Dec. 22, 1964 5. AZZOLARI 3,162,027

DEVICE FOR EFFECTING THE NARROWING IN KNITTING MACHINES AND SUCHLIKE Filed Dec. 28, 1960 4 Sheets-Sheet 4 INVENTOR 20/ /Z0 Guido ,4 oiarj United States Patent DEVICE FOR EFFECTING THE NARROWING IN KNITTING- MACHINE AND SUUHLIKE Guido Azzolari, Bergamo, Italy, assignor, to Fabrique National dArmes de Guerre, Societe Ananyme, Herstal, near Liege, Belgium V a Filed Dec. 28, 1966, Ser. No. 79,040 Claims priority, application Htaly, dan- 5, 1968, Patent 860; Dec. 12, 19.64}, 21,303/60 4 Claims. (Cl. 6648) On knitting machines and suchlike, the articles are knitted by a continuous method and subsequently separated and finished in the conventional way.

As a result of this continuous operating'method, the knitting operation must produce in succession and in a continuous manner: the welt with insertion of an elastic thread, the leg, the heel, the foot, the toe, the unthreading row and the separation row, this sequence being continuously repeated. in order to ensure an uninterrupted operation. By unthreading row is meant a step in the knitting process consisting in retracting all the threads but'one and in knitting a few rows with said thread before knitting the subsequent separation rows between two socks;

Considering that, during the narrowing phase, the needles supported by the channels of a needle cylinder are normally and periodically driven by a reciprocating motion, the operation of the various feeds, respectively of the various threads, results from the program which determines the verticaldisplacements of the needles in co-operation with the movements of the thread-guides.

In the course of all knitting operations, the needles are moved up and down by means of adequately shaped earns, the co-operation between the needles and some of these cams being controlled by transverse pushers which in turn are controlled by rotating drums fitted with removable projections and the position of which is determined by the particular pattern to be obtained.

The present invention is solelyconcerned with the steps, and consequently with the parts of the machine in connection with the knitting operations on a fraction of the periphery of the needle cylinder, i.e. with the steps and mechanical devices by means of which it is'possible to effect the narrowings. The steps are understood as those in the knitting process which comprise'knitting on a fraction of the periphery of the needle cylinder.

For this purpose, use is made in a WQYVWhlCh has already become quite conventional, of complementary cams which are part of the operational device, and of mobile elements co-operating with aforesaid cams for selecting the needles. Such operational device is to be understood the commonly employed cam cylinder which positively commands, respectively co-ordinates, the various devices ment lies in the, easy way in which this device can be constructed, assembled and disassembled, as the mechanism in question constitutes a unit of its own which can {be mounted as such in' its properlocation on the machine.

"It'follows therefrom that, according to the present invention, the special, compact device whichensures the rectilinear movements of the needles in the steps, respectively in the zone of narrowing, substantially. consists of the following combination: a support which'is common to two oscillating devices; connected to aforesaid common support and in co-operation with aforesaid oscillating devices, two mutually spaced cams between which a third fixed cam is inserted, a rigid connection being established between the oscillating systems, and these various elements being such, that when one of the oscillating ele ments lies in the path of the projecting butts of the needles carried by the rotating ring which forms the common support of aforesaid needles, the other oscillating device is withdrawn from aforesaid trajectory.

The result is a device which has the advantage of being compact, of operating systematically and of being positively controlled in its various movements.

The particular characteristic features of the device conforming to the present invention will appear more clearly from the detailed description of'one form of embodiment with reference to the appended drawings, in which? FIGURE 1 is a perspective view of a machine which is particularly well adapted to apply the device accord ing to the present invention;

FIGURE 2 is a perspective and enlarged view of part of FIGURE 1 and namely of the knitting head of this machine;

FIGURE 3 is a side View of the device according to the present invention;

FIGURE 4 is a top FIGURE. 3

FIGURES 5 and 6 are sections along straight lines V'V and VI-VI of FIGURE 4, respectively in the directions of the arrows;

FIGURES 7 and 8 are schematic representations of view of the device according to the relative motion of the needles in both directions of rotation of the needle cylinder;

FIGURE 9 is a conventional representation of the relative position between a row of needles and the cams of the device according to the present invention.

In the machine as it is represented in FIGURE 1, the actual knitting head 1 is supported by the general frame 2 of the machine. The'knitting head is fed by the bobbins 3 via the rack of countershafts 4. The various mechanisms of the machine are driven by an electric motor (not represented) housed in the base of the machine and whose pulley 5 drives by means of a belt 6 either the keyed or the loose pulley 7-8 mounted on the drive shaft 9 of the machine. The knitted work '10 is collected in an appropriate container 11. 1 q

The device according to the present invention, specially designed for ensuring the narrowing in the knitted work, is a completemechanical unit applied as a whole in front of'the appropriate part of the rotating cylinder which constitutes the common support of the needles, and in the present instance in the location 12. in FIGURES l and 2. In this particular case, this device consists of a support or small frame 13 which has an arcuate portion 14 the rear part of which is provided with a profiled band 15 in one or several parts, the upper edge of which is ground to form a cam according to the verticaldisplacements tolbe imparted to'the needles in the zone corresponding to aforesaid devices, during their rotary movement.

Onto the front part of portion 14 are fixed the three mutually spacedacams 164748. These cams are designed and disposed in such way that, when the device conforming to the present invention has beenfitte'd in place, the camsli-fl and ldare located on the. path of the projecting butts 19 of the needles 25). The profiled band 15 is fastened to the portion 14 by screwsgl, and the cams 1647-13 are fixed to the same'portionl l by screwsZZ-23-Z4 respectively. The support or frame 13 I is provided with lugs 2526 into which holes 27-23 V respectively have been drilled to accommodate the fixing bolts with which the device can be fastened to the corresponding parts of the general machine.

Lugs 25-26 are each provided with a tubular upright 29-39, respectively, into which a mobile oscillating picker lever device is engaged. Each of these devices substantially consists of a pivot 31 mounted in one of the tubular uprights 29-30 and prevented from moving upward by means of an annular stop 32, and from moving downward by means of a prismatic head 33 provided with a deep longitudinal groove 33'. This prismatic head carries a pivot 34 about which one of the ends of an oscillating picker lever 35 can swing and the other end 36 of which duly shaped, is, in one position, disposed on and across the underlying cam 16, 17 respectively. This oscillating lever 35 is acted upon in a way that its free end is pressed against said cam 16, 17 respectively by a return spring 37 which is fastened at one end on a point of said oscillating lever 35 located under pivot 34, and the other end, to a point of said head 33, said spring 37 being thus retained in said groove 33'. The prismatic head 33 carries a stud 38, 39 respectively. These two studs 38-39 are connected by means of a rod 40 into which slots 41-42 have been provided for alfording a passage to the studs 3839. Said rod 40 may either be in one of two parts. In the latter case, these two parts are mutually assembled in relative positions which can be varied and adjusted.

In one characteristic position of the mobile and oscillating elements, said studs 3839 are disposed against the bottom of the slots 41, 42 respectively, directed toward the extremities of the rod 40. The compact device which has thus been constructed, is fastened facing the grooved rotating cylinder 43 which constitutes the common support of the needles 20 under a zone which is served by an element of the thread-guiding device, and preferably under the thread-guide related to the main feed.

The operation of this device is quite simple and can be explained in the following Way, particularly with reference to FIGURES 3, 4, 7, 8 and 9. For clearness sake, in FIGURES 7 and 8, the path of the needles contacted by the narrowing device is represented by full-line arrows, whereas the path of the needles which remain at work are indicated in broken-lines. Normally, the grooved cylinder 43, together with the needles 20, rotates in the direction of arrow F (FIGURE 4), which is counter-clockwise. According to usual practice all needles with short butts contact cam 17, follow the upper outline of the latter, are brought down by the central cam 18, and continue moving downward and are finally brought back into their normal position by following the lower faces of cam 16. It should be understood that, during this continuous rotation of the needle cylinder, the device which is the object of the present invention is in the position represented in FIGURES 3 and 4, that is the shaped free end 36 of the lefthand lever 35 is actually facing the corresponding cam 16 Whereas the righthand lever 35 is, under the action of the connecting rod 40, disposed in such way that its shaped free end 36 is contacted with respect to the corresponding cam 17, i.e. that this free end is not in the path of the projecting butts 19 of the rotating needles. As long as said needle cylinder rotates counterclockwise in a continuous way, i.e. as long as the machine knits over the whole periphery'of the needle cylinder, the device which constitutes the object of the present invention is idle and fulfills no function, except that the cams participate in the operational device which determines the vertical movements of the needles so as to bring them into or remove them from the zones corresponding to the picking-up of a thread for forming a stitch. In fact, the device conforming to the present invention is only fully used in the narrowing phases, when the number of stitches per turn of the cylinder is gradually diminishing row after row.

In order to eifect this, at-least one needle of each row must be taken out of service, considering that the result therefrom is that the respective lengths of the rows decrease each time by one stitch. With this object in view, and through the action of the driving and operational device of the machine, when a narrowing step is to start, the grooved needle cylinder 43 which carries the needles, instead of rotating in a continuous way in the well known manner, is subjected to a reciprocating motion of constant amplitude. But, when the direction of rotation of the needle cylinder 43 is reversed, i.e. when it starts moving in the direction of arrow F, i.e. clockwise, the result therefrom is that the heel of the first needle 20 which meets the free end 36 of the oscillating lever 35 located in its trajectory takes this needle along and compels it to follow the contour of the corresponding profiled band 15. This profile is designed in such a way that it causes the end 36 of the lever 35 to rise, which end then in turn displaces the corresponding needle upward so as to bring it into a position in which it can not pick-up a thread nor form a stitch. This will automatically reduce this row by one stitch. But, during its rotation about its pivot 31, the oscillating lever 35 has exerted a pull on rod 40 which latter has caused the righthand oscillating lever 35 to swing in opposite direction about its corresponding pivot 31 so that, at the end of this movement, the free end 36 of the lefthand oscillating lever has been eclipsed from the trajectory of the projecting butts 19 of the needles 20, whereas the free end 36 of the righthand oscillating lever has on the contrary been brought into this path. Thus, when during its oscillating displacement the needle cylinder 43 of all needles moves in the direction of the arrows F, the same method will take place as during the preceding displacement, but in opposite direction. Another needle will thus have been made inoperative, the number of such narrowings being progressingly rising row by row as long as the needle cylinder is carrying-out an alternate rotary motion, which is determined by the operational mechanism of the machine according to the articles to be manufactured.

It will be appreciated that the device conforming to the present invention thus really constitutes a complex device in which are grouped and fastened to one and the same support the cams and the oscillating elements, which will effect the advantages.

On account of this device, a particular precaution will have to be taken when a progressive increase of the num+ ber of stitches is considered, in order to bring back the knitting process onto the complete periphery of the needle cylinder 43. In a general way, this increasing device causes in fact the needles to be progressively brought back into service one by one during the reciprocating motion of the needle cylinder with same amplitude. But as, during this phase of increase, the narrowing device which is the object of the present invention, goes on working, the increasing device will have to be adjusted in such way that it progressively reintroduces the needles two by two, as at the same time the narrowing device removes them one by one, so that the final result will be that of a mechanism which on the one hand increases the number of active needles progressively two by two and on the other hand decreases their number simultaneously one by one, the net result of both simultaneous operations being that the number of needles is increased one by one in each row during the whole phase of increase. This is not a disadvantage, by any means, considering that on the contrary this simple precaution makes it possible to keep the narrowing device, which is the object of the present invention, in a permanent condition without the slightest difiiculty during'or on account of the phase of increase, this narrowing mechanism operating automatically by the simple fact that the needle cylinder '43, in-

stead of rotating in a continuous way, is being imparted 5 1 variable and that these elements can be replaced by equivalent parts or by parts fulfilling the same functions without departing from the scope of the present invention.

What I claim is: I 7

1. In a circular knitting machine having a rotary needle cylinder, a narrowing device consisting of a compact unit comprising a frame having an arcuate portion concentric with said needle cylinder, needle cams on a concave'f ace of said arcuate portion, two uprights on said frame, a picker lever pivotally and oscillatably munted on each upright, said picker levers being interconnected, and guiding means for said picker levers on a convex face of said arcuate portion.

2. Improved narrowing device according to claim 1, in which said cams are screwed on said concave face of said frame.

3. Improved narrowing device according to claim 1, in

6 which said guiding means for the picker levers are positioned on said convex face of the frame and at leasthalfway between the free extremity of the picker levers and their pivoting point. 7

4. Improved narrowing device, according to claim 1, in which said guiding elements are fixed to the convex face of said frame by means of screws securing the said cams.

References Cited by the Examiner UNITED STATES PATENTS 1,152,850 9/15 Scott 66-48 1,841,265 1/32 Page et al. 6648 1,847,592 3/32 Butz 66-4 RUSSELL C. MADER, Primary Examiner.

DONALD W. PARKER, Examiner. 

1. IN A CIRCULAR KNITTING MACHINE HAVING A ROTARY NEEDLE CYLINDER, A NARROWING DEVICE CONSISTING OF A COMPACT UNIT COMPRISING A FRAME HAVING AN ARCUATE PORTION CONCENTRIC WITH SAID NEEDLE CYLINDER, NEEDLE CAMS ON A CONCAVE FACE OF SAID ARCUATE PORTION, TWO UPRIGHTS ON SAID FRAME, A PICKER LEVER PIVOTALLY AND OSCILLATABLY MOUNTED ON EACH UPRIGHT, SAID PICKER LEVERS BEING INTERCONNECTED, AND GUID- 